An introduction to transcription… DNA REPLICATION NOTES An introduction to transcription…

Nucleosomes Nucleosomes fold A LOT of DNA into a small space They also seem to be able to help genes be “read” to produce certain proteins (THIS WILL BE VERY IMPORTANT LATER!) http://www.youtube.com/watch?v=4jtmOZaIvS0

DNA Replication DNA needs to make copies of itself The structure of DNA lends itself to this! DNA can “unzip” between the base pairs Each side of DNA serves as a template for the new DNA strand. In prokaryotes this happens at one point In eukaryotes this happens at many points along the DNA

DNA Replication DNA Replication is carried out by a series of Enzymes An enzyme is a protein molecule in a plant or animal that makes “reactions” in a cell happen without actually “Reacting” itself (OLD NEWS!) The main enzymes in DNA replication are Helicase which “unzips” the DNA double helix by breaking the H-bonds between nucleotides; and DNA Polymerase which puts together DNA

DNA Replication http://www.contexo.info/DNA_Basics/replication%20move.htm

DNA Replication Each new strand must match the original “Spare parts” from the cell attach to the old DNA strands Spare parts are base pairs and the backbone of DNA (Nucleotides) Adenine aligns with Thymine and Guanine with Cytosine. (And vice versa) What new base pairs would “hook up” with a strand that had base pairs of aaggtgcgtcagtca ttccacgcagtcagt

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